Vitamin C treatment reduces elevated C-reactive protein.
Plasma C-reactive protein (CRP) is an inflammatory biomarker that predicts cardiovascular disease. Lowering elevated CRP with statins has reduced the incidence of cardiovascular disease. We investigated whether vitamin C or E could reduce CRP. Healthy nonsmokers (N=396) were randomized to three groups, 1000 mg/day vitamin C, 800 IU/day vitamin E, or placebo, for 2 months. Median baseline CRP was low, 0.85 mg/L. No treatment effect was seen when all participants were included. However, a significant interaction was found, indicating that treatment effect depends on baseline CRP concentration. Among participants with CRP indicative of elevated cardiovascular risk (> or =1.0 mg/L), vitamin C reduced the median CRP by 25.3% vs placebo (p=0.02) (median reduction in the vitamin C group, 0.25 mg/L, 16.7%). These effects are similar to those of statins. The vitamin E effect was not significant. In summary, treatment with vitamin C but not vitamin E significantly reduced CRP among individuals with CRP > or =1.0 mg/L. Among the obese, 75% had CRP > or =1.0 mg/L. Research is needed to determine whether reducing this inflammatory biomarker with vitamin C could reduce diseases associated with obesity. But research on clinical benefits of antioxidants should limit participants to persons with elevations in the target biomarkers.
Block
Gladys
G
University of California, Berkeley, 94720, USA. gblock@berkeley.edu
Jensen
Christopher D
CD
Dalvi
Tapashi B
TB
Norkus
Edward P
EP
Hudes
Mark
M
Crawford
Patricia B
PB
Holland
Nina
N
Fung
Ellen B
EB
Schumacher
Laurie
L
Harmatz
Paul
P
D000328:Adult; D000367:Age Factors; D001205:Ascorbic Acid / Q000008:administration & dosage* / Q000097:blood; D015415:Biomarkers / Q000097:blood*; D015992:Body Mass Index; D002097:C-Reactive Protein / Q000032:analysis*; D002318:Cardiovascular Diseases / Q000097:blood* / Q000175:diagnosis / Q000188:drug therapy; D005006:Ethnicity; D005260:Female; D006801:Humans; D008297:Male; D008593:Menopause; D008875:Middle Aged; D012737:Sex Factors; D014810:Vitamin E / Q000008:administration & dosage* / Q000097:blood
D015415:Biomarkers; D014810:Vitamin E; D002097:C-Reactive Protein; D001205:Ascorbic Acid